The present invention relates to a method using a distributed, virtual disk storage system to move data among storage devices.
A storage area network (SAN) operates, in effect, as an extended and shared storage bus between hosts and storage devices to offer improved storage management, scalability, flexibility, availability, access, movement, and backup. Storage virtualization in the SAN further improves storage through the separation of host system views of storage from physical storage. In a virtual storage system, the hosts connect to the storage devices through a virtual disk that maps to the data on the storage devices. This allows new storage management value to be introduced, including the ability to migrate data among physical storage components without effecting the host view of data. As a result, data may be repositioned within a storage device or copied to a separate storage device seamlessly, without significantly affecting the operation and performance of the host. To take advantage of the new virtual storage, it is the goal of the present invention to provide an improved methodology for moving data within the storage devices.
It is a further goal of the present invention to provide a methodology for seamlessly migrating data files in virtualized storage networks using parallel distributed table driven I/O mapping. These systems concurrently use multiple copies of a mapping table. A main challenge of data migration in a distributed virtual network is coordinating the separate copies of the mapping table so that the host does not effect the data during migration and have access to the moved data after migration. Current solutions exist in architectures that are not distributed among hosts or not distributed across storage subsystems.